The planned missile defense system will be used solely to intercept ballistic missiles targeting Japan, not missiles that pass over Japan and target other countries -- including the United States, according to government sources.
The government has decided to limit the operational scope of the system, to be purchased from the U.S. and deployed by fiscal 2007, because intercepting missiles targeted at other countries could be construed as collective defense.
According to the government's interpretation, Japan has the right under international law to collective defense -- the right to use force to counter a foreign attack on an allied country -- but the war-renouncing Constitution forbids the exercise of that right.